An LTE (Long Term Evolution) technology provides various IP (Internet protocol) based services, such as a voice over IP (VoIP, Voice over IP) service and a best effort data service. As an IP based transmission mechanism provides various services, the LTE optimizes transmission of the IP based services. For example, for the VoIP service, a transmission latency, a transmission period, signaling scheduling overheads, a user capacity, and the like of the service need to be considered. The VoIP service generally has a constant packet arrival period, for example, a typical value is 20 ms. The LTE defines various physical channels at a physical layer to transmit various messages, for example, a PUSCH (Physical Uplink Shared Channel), a PDSCH (Physical Downlink Shared Channel), a PUCCH (Physical Uplink Control Channel), and a PDCCH (Physical Downlink Control Channel). For a data channel, a basic TTI (Transmission Time Interval) is one subframe. One subframe is 1 ms and includes two timeslots. In each TTI, different UEs (user equipment) can use different frequency resources to share the TTI.
For a TDD (Time Division Duplex) system, one frame is 10 ms and includes 10 subframes, and each subframe is 1 ms. The subframes include a normal subframe and a special subframe, and the special subframe includes three parts: a downlink pilot timeslot, a guard interval, and an uplink pilot timeslot. An existing TDD system has an uplink/downlink subframe configuration, and uplink/downlink subframe configurations corresponding to a configuration 0 to a configuration 6 are shown in the following table:
Uplink/downlinkSubframe numbersubframe configuration01234567890DSUUUDSUUU1DSUUDDSUUD2DSUDDDSUDD3DSUUUDDDDD4DSUUDDDDDD5DSUDDDDDDD6DSUUUDSUUD
D represents a downlink subframe, S represents a special subframe, and U represents an uplink subframe.
In the TDD system, for a latency-sensitive service such as a VoIP service, as the service has a requirement of a transmission latency and the service needs a specific scheduling period, resources that can be used to schedule a same data packet are limited, leading to low coverage performance of a signal.